Heretofore, there has existed the problem in the making of gears or splines which are out of concentricity and wherein, diametrically opposed radii are different. If a gear is out of concentricity and is brought together in mesh with another gear, also out of round, the result is that there is a non-uniform pressure applied to all of the teeth of the gears during operation thereof. Other problems include distortion and non-uniformity of gear teeth. This may be caused by heat treatment, inaccurate cutting of teeth, poor cutting tools or material, different tools or other causes.
As exemplified in the prior art such as the following United States Patent Nos.:
2,942,389 3,006,117 PA1 3,092,935 3,293,805,
the grinding gear also rotatively drives the workpiece gear and, therefore, is at all times in pressure contact with the workpiece teeth throughout all diameters and length of teeth as well as along the involute of the gear or spline. It is undesirable for the workpiece to be rotatably driven by the grinding or other type finishing gear especially when, in the beginning of the grinding or finishing, only certain areas need correction. The grinding gear function must be limited to cutting of the workpiece and not used to drive the workpiece.